Apple's IPod
Faces Challenge
From Cellphones

With its white-hot iPod device, Apple Computer Inc. sits atop the digital music world -- seemingly without a serious competitive threat in sight.

That lead may not last much longer. Apple will soon confront not just a new challenger but an entire $100 billion industry. Cellphone makers and wireless carriers are piling into mobile music, with an array of new services and phones that could radically change a game that until now has been defined largely by Apple.